Field glass and protective cover therefor



Sept. 6, 1949. s. 4caLAUsriR' 2,481,409

FIELD-GLASS AND PROTETIVE COVER THEREFOR Filed May 1s, 1947 PatentedSept. 6, 17949 UNITE-o FIELD' GLASS AND PROTECTIVE oovnlt THEREFoRsamuel Glauser, Le Locre, switzerland Application May 13, 1947,Serial'No. 747,711 In Switzerland April 11, 1947 3' Claims. 1

Theobiectof the present invention isA a fieldglass,particularlyj apocketsize field-glass, characterisedinthat ity comprises an optical systemarranged in acasing and. a device enabling to cover at least. such partsof the optical system, as left uncovered bythe casing and forming anintegral part of the iield-glasstI The drawing represents, by way ofexample, one executionalform of the field-glass according to theinvention.

Fig. 1 is an elevation,

Fig. 2 is a, section through the axial plane of the lenses,

Fig.. Slis a. plan, and

Fig,l 4 is a. sectional view taken on section line IV--IV ofv Fig. 1.

The represented: field-glass comprises a casing member I. shapedygenerally asiaY square parallelepiped and in which are housed thecomponents forming.Vv its` optical. system, viZ.: an eyepiece mounted ina tube 2v arranged toV slide in the bore 3 of casing I, when-operatingar knurled nut 4 which is lodged in a recess 5 of the casing, aset-screw S engaging into a longitudinal groove 'I of tube 2toprevent'the latterA from rotating; a prism 8 lodged in a recess orchamber 9. of the casing' I', where' it is` fastenedV by means of' abent laminated spring I'Il which acts on the prism through a layer IImade of soft material, rubber for example, and finally an objective I2fastened' in its aperture or seat' by means of nut I3.. The axis of theoptical system. is represented by the dash-dottedY line I4. The Figures2V and 4 show that the outlines of the casing depart in their detailsfrom the parallelepiped mentioned before. Thus, the small' facecontaining the axis of the eyepiece. is a semicylinder. Furthermore, thecasing I is xed -by non-represented screws in a sheet metal piece orcasing. shell I6 comprising ridges I1, the purpose of which Will bedescribed. hereinafter. The assemb-ly of casing I and of this piece I6is mounted telescopically in the protective cover I8, which is also madeof sheet-metal. In its retracted position, as represented in thedrawing, the end faces I9 and 2Ilof this protective cover serve to coverthe eyepiece and the objective I2, in order to protect them againstpointed objects and dust. In the withdrawn position, the face 20 clearsthe eyepiece, whereas the circular opening 2| provided in the face I9 ismoved in front of the objective I2. Now the field-glass is ready foruse. The adjusting nut 4 for focussing the eye-piece, always slightlyprojects outwardly through a slot in the sheet metal piece or shell I6opposite to the recess 5. of the casing I, in` order to be manipulatedwith the forenger'- and the thumb of the handfholdingthe. field-glass;

A helical spring 22 is lodged in a. recess 23y of casing I, inV which itisA supported` at. one end in order toexert by itsother end a, pressureagainst the protective cover I8. A push buttony 24, arranged at the freeend of. a laminated spring 25 xed on said coverf I8, mutually locks.`the casing I and the cover I8 in the retracted position, by engagingintoahole 26 provided for this purpose in casing shell l-I,y and in thecover I8; order to limit the withdrawal or extension, a plunger 2lsliding` along a bore` 28\of casing I is provided, the abutmentl of saidplunger meeting at the end of the stroke anannular nut 29, screwed intothe wallof said bore. The cover I8 isA xed to the stem.I ofc plunger 21.byY means of a nut 3i! and a lock nut 3|. When it isrequired to retractthe casing, I: into-.the cover I8, it is pushed home inside the latterwhichv then contacts the ridges or stops I-'I of sheet metal piece orshell It. In order to effect the extension or withdrawal, the button 24is pressed.l It is easily possible to hold the field-glass, to adjustthe nut 4. to operate the retraction and.l the withdrawal with thenngers and the-palm` of one hand.

The faces of cover I8- sliding on casing shell It are connected toAeach. other by av semicylinder made of sheet metal- The shape and thedimensions of the field-glass are such that it may easily be carried ina pocket of a garment.

The field-glass described is: only one of the numerous possibleexecutional'; forms. The protective devcefcould-be mountedv on thecasing by means of; pivots for example; itv could also comprise lidsmounted rotatably on` hinges fixedl to the casing, or discs pivotallymounted on the casing; it would alsofbepossible to` providel diaphragmsin front of the parts of the optical system left unprotected by' thecasing. of the type as used in photographic cameras.

All these protective devices may be adapted to monocular or binocularfield-glasses fitted with an optical system similar to or different fromthe in retracted position With respect to said cover; said casing havingan aperture extending a short distance into the latter adjacent to theinner end of said casing in one portion thereof and hav-1 ing an openbore extending a predetermined distance into said casing adjacent to theouter end of the latterin an .opposite portion thereof, with the centralaxes of -the aperture and bore substantially parallel but spaced apartout oi alignment;V an optical element seated in said aperfV ture; asecond optical element disposed Within said bore; said cover havinganaperture adjacent to the outer end upon one portion thereofregistering with the iirst mentioned-,opticalelement` in the aperture ofthe casing in extended position of the latter, While the open .endxof.the corre-` spondingly opposite portion of said cover simultaneouslyclears the second optical element in to'said cover; stop means forlimiting'tl'ie retrac-` tion of said casing to a predetermined retractedposition in said cover; manually'releasable latch means for retainingsaidcasing in retracted position With Vrespect to'said cover; saidcasing having an apertureextending a short distance into the latteradjacent tof-the inner end of Vsaid casing vin one portion thereofandhaving an open bore extending aV predetermined distance into saidcasing adjacent to the outer end of the latter in an opposite portionthereof, with the central axes of the apertureand boresubstantiallyparallel but spaced apart out of alignment; said casing alsoV having-aninterior chamber extending from the aperture to'f the bore thereof andcommunicating With-the inner ends of said aperture and bore; an opticalelement seated in said aperture; a second optical elementr disposedwithin said bore; said cover having an aperture adjacent to the outerend upon one portion thereof registering with the yir'st' mentionedoptical element in the aperture'ofthe casingin extended position of thelatter, While the open end of the correspondingly oppositemp'ortion ofsaid cover simultaneously clears the second optical element in the boreof Vsaid casing; and "optical reflecting means disposed in said interiorchamber for conducting light rays from one optical element to the other.Y

3. A telescoping field-glass including the combination of a hollowVprotective Vcover which is "4 open at one end; a corresponding casingshell having an open inner end and extending a distance into the coverin retracted position and adapted to be slidably extended a limiteddistance from the open end thereof; a casing member secured in thecasing shell and together therewith forming a casing proper means urgingthe casing into extended position; manually. releasable latch means forretaining said casing in retracted position in said cover; the casingVshell having a pair of ridges upon the opposite sides adj acent'to andsubstantially parallel to the closed end thereof Vforming stops for theend edges of the open end of said cover to limit the retraction `of saidcasing to a predetermined retracted position; means inlsai'd coverengaging with an interior portion of said casing for limiting theextension thereof to a predetermined extended positionfsaid casinghaving an aperture extending a short distance into the latter adjacentto the inner end of said casing in one portion thereof and having anopen bore 'extending a predetermineddistance into said rcasing adjacentto the outer end of the latter in an opposite portion thereof, with thecentral axes of the aperture and bore substantially parallel but spacedapart out of alignment; an objectiveseated in the aperture; anadjustable eyepiece movablydisposed Within the bore; the casing alsohaving an interior chamber Within the casing member thereof extendingfrom the aperture tothe bore and communicating Withr the inner endsthereof; said cover'having an aperture adjacent to the outer e'nd'uponone portion thereof registering With'the rst mentioned optical elementin the aperture'of thel casing in extended position ,of theV latter,While the open end of the correspondingly opposite portion of said coversimultaneously clears the second optical element in :the bore of saidcasing; and an optical reiiecting member located in the interior chamberfor transmitting light rays from said objective to said eyepiece. Y 'lSAMUEL GLAUVSER.

REFERENCES ,oITED The following references are of record in the I ileofV this patent: o V

Y n UNITED STATES PATENTS Number

